Means and method to promote blood and lymph circulation in pressurized suits



Nov. 26, 1968 N. A. M LEOD 3,412,730

MEANS AND METHOD TO PROMOTE BLOOD AND LYMPH CIRCULATION IN PRESSURIZED SUITS Filed Dec. 8, l965 2 Shets-Sheet 1 Norman ,4. 1 46:1004.

INVENTOR.

WHANN d M MANI6AL lH/ornejs for A ly/ken) N. A. MuCLEOD 3,412,730 MEANS AND METHOD TO PROMOTE BLOOD AND LYMPH CIRCULATION IN PRESSURIZED SUITS 2 Sheets-Sheet 2 Nov. 26, 1968 Filed Dec. 8, 1965 Norman ,4. Mad e04 INVENTOR. WHANN 6 Ma MANIGAL A/r'orneys for A I/Ean/ United States Patent Office 3,412,730 Patented Nov. 26, 1968 3,412,730 MEANS AND METHOD TO PROMOTE BLOOD AND LYMPH CIRCULATION IN PRESSURIZED SUITS Norman A. MacLeod, La Habra, Califi, assignor of thirty-six percent to R. Walton Whann, Los Angeles, and ten percent to Frank F. Reed, Pasadena, Calif.

Filed Dec. 8, 1965, Ser. No. 512,403 Claims. (Cl. 128-40) This invention relates to a means and method for increasing blood and lymph circulation in astronauts wearing pressurized suits.

The enforced inactivity during space travel accompanied by the loss of gravitational loading on the body tends to produce a condition in a man on a long space flight similar to that of the condition produced by a prolonged confinement in bed. During such prolonged muscular inactivity, there is a loss of calcium and a serious circulatory impairment in a human body.

The circulation of blood and lymph can be assisted by varying the pressure on the body from positive to negative in rapid sequences. These may be done ordinarily by enclosing the limbs in a rigid pressure tank, as disclosed in my United States Letters Patent No. 3,094,983, for Blood Circulation Device and Method. An astronaut, however, must have a continuous freedom of movement even when wearing a space suit and such prior means and method are not applicable to a space suit which must be flexible.

Although space suits are flexible, they can easily sustain a positive pressure up to lbs. per Square inch, but if they are completely flexible, negative pressure cannot be used in the suit in that it would cause it to collapse against the body of the wearer. Thus, for example, when a limb is enclosed in a flexible container only positive pressure pulses can be applied and these act against the arterial blood flow into the limb.

It is an object of this invention to produce all of the beneficial eifects of positive and negative pressure cycling on the limbs, and even the lower torso, of an astronaut wearing a pressurized space suit so as to cause healthy tissue movement and to assist blood and lymph circulation.

It is another object of the invention to provide an improved pressurized suit.

It is still another object of the invention to provide a space suit which is divided into two or more portions, one of which completely encloses the upper torso and head, and the other of which encloses the limbs. The latter portion may also enclose the lower torso. If a space suit is pressurized to generally, for example, 10 lbs. per square inch, this can be maintained in the upper torso and head portion, but that portion containing the limbs and/or lower torso can have the pressure varied above and below 10 lbs. per square inch as, for example, from 13 lbs. per square inch to 7 lbs. per square inch. This would cause the limbs to be subjected to an alternating pressure cycle of plus or minus 3 lbs. per square inch with respect to the upper torso and head.

It is a further object of the invention to provide a pressurized suit, as described in the preceding paragraphs, for bed-rest patients. In such a suit the general pressure may be maintained at several pounds higher than that of atmospheric pressure. The suit will'be of value in treating emphysema, a condition of the lungs in which the ability to perform the normal functions of oxygen absorption and carbon dioxide emission is adversely affected. Concomitant with this is a reduction in the victims ability to exercise his body, and a lowering of circulatory efficiency thereby results. By raising the pressure in the suit to several pounds per square inch above atmospheric pressure, the rate of oxygen absorption by the lungs will be increased. Varying the pressure in the limb portion of the suit above and below the pressure in the head and upper torso will cause tissue movement and promote blood and lymph circulation.

General suit pressures as high as 10 lbs. per square inch above atmospheric pressure could be used in such treatments although pressures of only 2 to 4 lbs. per square inch would produce significant results.

Such a method of treatment would also be beneficial to patients having heart disease and those suifering from the general debility of old age.

Further objects and advantages of the invention may be brought out in the following part of the specification wherein small details have been described for the competence of disclosure, without intending to limit the scope of the invention which is set forth in the appended claims.

Referring to accompanying drawings, which are for illustrative purposes:

FIG. 1 is a front elevational view of a pressurized suit according to the invention;

FIG. 2 is a fragmentary cross-sectional view, taken substantially as indicated by line 2-2 in FIG. 1;

FIG. 3 is an enlarged cross-sectional view of the valves shown in FIG. 2;

FIG. 4 is a fragmentary view, partially in cross-section, of an alternate means to vary the pressure in the limb portions of the suit shown in FIG. 1;

FIG. 5 is a fragmentary cross-sectional view of .a means to seal one portion of the suit in FIG. 1 from another;

FIG. 6 is a fragmentary cross-sectional view of an alternate embodiment of the limb portion of the suit shown in FIG. 1;

FIG. 7 is a fragmentary view of an alternate type of limb portion of the suit shown in FIG. 1;

FIG. 8 is a cross-sectional view, taken as indicated by the line 88 in FIG. 7;

FIG. 9 is a view of a type of flexible material usable for the limb portions of the suit; and

FIG. 10 is a fragmentary view of a variation of the material shown in FIG. 9.

Referring again to the drawings, there is shown in FIG. 1 a space suit generally designated as 10. Space suits may be made of rubberized cloth so that a pressure seal may be maintained or the suit may be made of similar elastomeric materials to provide flexibility and ease of movement for the wearer. They also may be made using varying amounts of metal which may be imbedded in elastomeric materials for ease of sealing and for flexibility.

The space suit shown has an upper torso and head portion 11 and two limb portions 12 and 13, for the arms and the legs, respectively. Each of the arms and legs and the inside of the portions of the suit covering them are sealed from the torso and head and the inside of the portion of the suit covering them. The seals are shown at 17, 18, 19 and 20 in FIG. 1, and in an enlarged view of the seal 20 in FIG. 2. Each of the seals, as indicated in FIG. 2, is made of an annular band 21 of elastomeric material such as adapted to snugly fit on the leg or arm on which it is intended to be used. Extending radially outwardly from the seals outer circumferential surface is an annular flange 23. In the case of the seal 20, the upper side of the flange abuts an annular flange member 24, integral with the torso portion of the suit above the seal, and the lower face of the flange 23 abuts a flange 25 integral With the leg portion 13 of the suit. Above the flange 24 and below the flange 25 are relatively rigid metal rings 26 and 27. The rings and the three flanges are sealingly secured together by a plurality of circumferentially spaced bolts 30.

Space suits generally have other layers of material, additional to the outer sealing layer, shown in FIG. 2, as

the torso portion 11 and the leg portion 13. Irrespective of the layers of material, other than the outer layers shown, the skin of the upper leg 31 and of the lower leg 32 is etiectively proximate to the sealing layer of the suit so that there is relatively little air space between the skin and the suit, as indicated in FIG. 2.

Between each of the portions of the suit and portions of the body which are sealed from each other, such as an arm and the torso or a leg and the torso, there are a pair of oppositely closing, spring loaded check valves, as 35 and 36, as shown in FIG. 2. An enlarged view of the valve 35 is shown in FIG. 3, the valves 35 and 36 being identical. The valves 36 are not shown on the suit in FIG. 1 in that they are somewhat rearwardly of the valves 35 but are positioned for comfort so that the astronaut may sit down and lean backwardly without pressing against them.

The valve 35 is open to the torso portion of the suit by means of an aperture 37. Inwardly of the aperture 37 is an annular seat 38 upon which the valve disc 41 is held in closed position by means of a spring 42 and an adjusting screw 43. The valve 35 is set to open against the force of the spring when the pressure in the torso portion of the suit is, for example, 3 lbs. per square inch greater than the pressure in the limb portion of the suit. The air, or other life-sustaining gas used, in the torso will then flow into the limb portion of the suit through a tube 44, sealingly secured to the latter at 47. Each of the other valves 35 is positioned and set to operate in the same way with respect to the torso and adjoining limb.

The other valves 36 are reversely positioned and each is set to open when a respective limb portion has a desired pressure, for instance, 3 lbs. per square inch greater than that in the suit portion surrounding the torso. The gas in the limb portion will then flow through a tube 48 which has one end connected to the valve and has its other end seali-ngly secured to the torso portion of the suit at 49 in FIG. 2 Under such settings of the valves 35 and 36, the torso pressure would normally be approximately 8 lbs. per square inch.

An air purification system 50 supplies purified air or other oxygen mixtures to the pressurized suit by means of a constant delivery pump 53. Air is supplied directly to the torso and head portion 11 through a tube 54 having a shut-off valve 55. Fresh air is also supplied to the leg portions of the suit through tubes 56 and 59 having shutoff valves 60 and 61, respectively. The supply of air to the leg portions is generally for flushing purposes, and air may be moved from the leg portions to the torso by opening the valves or 36. In the same manner irrespective of the pressure, air may be moved through the latter valves into the leg portions from the torso when they are opened by means of the adjusting screws. Any unused air and the carbon dioxide is returned from the head and torso portion to the air purification system through tube 62.

To promote blood and lymph circulation, the pressure is varied in the limb portions 12 and 13 by means of a piston pump 65, having a cylindrical chamber 66 sealed at one end by a piston 67. A connecting rod 68 is secured at one end to the outer end of the piston and the other end of the rod is pivotally connected at 71 to a rod 72. The other end of the rod 72 is pivotally connected to an arm 73 at 74, the arm being rotated about its end 77 by a motor 78. The length of the stroke of the piston is determined by the position of the pivot point 74 on the arm 73. To provide a pressure variation from a normal of 5 lbs. per square inch in the limb portions to a decreased pressure of 2 /2 lbs. per square inch and an increased pressure of 7 /2. lbs. per square inch, the piston travel volume on suction must be equal to the volume of air in the limb portions plus the connections and the volume of the cylinder in front of the piston. Similarly on the compression stroke, the piston travel volume must equal one-third of the volume of air in the limb portions plus the connections and the volume of the cylinder in front of the piston to produce an overpressure of 2 /2 lbs. per square inch or an overall pressure of 5 lbs. per square inch.

If the piston travel is in excess of these limits, then the valves 35 and 36 will open it set at pressure limits of 2/2 lbs. per square inch and 7 /2 lbs. per square inch, thus preventing undesirable pressure variations.

The chamber of the pump is connected to a four-way discharge block 79 by means of a tube 80, the block being connected to the leg portions by tubes 83 and 84 and being connected to the arm portions by tubes 85 and 86.

In the operation of the space suit, there is a constant delivery of purified air to the torso and head portion by means of the pump 53 and at a constant pressure, for example, 10 lbs. per square inch. If the valves 60 and 61 are open, then the pressure to the leg portions would also be 10 lbs. per square inch. If it is desired, similar conduits may be connected to the arm portions so that the same pressure may be established in them. Where there is no direct connection to the arm portions from the air pump 53, the pressure can be developed in the arms by opening the valves 35 and closing them before the pump 65 is started. Similarly, when the pump 65 is started, the valves 60 and 61 are also closed.

Thus, to promote circulation of blood and lymph in the arms and legs, the same starting pressure may be caused to exist in the limb portion as in the torso and head portion. Then, if the pressure in the entire suit is 10 lbs. per square inch and the legs and arms are sealed from the head and torso portion, actuation of the pump 65 will increase and decrease the pressure in the arm and leg portions. For example, on the increase, the pressure of the limb portions may have a maximum of approximately 13 lbs. per square inch so as to tend to cause venous circulation to increase from the legs toward the heart. When the pressure is decreased in the limb portions to 7 lbs. per square inch, for example, the arterial flow from the heart to the limb portions is increased because the resisting pressure on the limbs is decreased. The cycling of the pressure variation need not be rapid since the pressure differential in the limb portions from that in the head and torso portion causes increased blood and lymph flow in one direction or the other. The desirable rate for pressure variation is from 10 to 60 cycles per minute.

Since astronauts are extremely healthy people, they normally have very good blood and lymph circulation, and it is probably necessary or desirable that the pressure be varied in the limb portions to promote circulation for about only a few minutes each hour. Experience will dictate the actual length of the period or periods that it will be desirable or necessary to vary the pressure in the limb portions to promote blood and lymph circulation.

The same kind of operation can be used on a bed-rest patient, especially where the patient has heart disease or emphysema and it is desirable to supply air or oxygenenriched air directly to the lungs at an increased pressure. Under such an increased pressure, the absorption of the oxygen by the blood stream is greatly increased and the patients lungs can more readily absorb the necessary oxygen for healthy body conditioning. At the same time, as indicated above, variation of the pressures in the limb portions would increase the circulation in the limbs.

In FIG. 4 there is shown a pump 65a, equivalent to the pump 65, and having a piston 67a connected to a rod 68a. The rod 68a is secured to an astronauts foot 89 so that the astronaut may obtain exercise at the same time the pump is increasing and decreasing pressures in the limb portions to promote circulation. The pump is connected to the tube in the same manner as shown in FIG. 1.

In FIG. 5 another type of seal is shown and which may be used to seal the limb portions from the head and torso portion in the same manner as do the seals 17, 18, 19 and 20. The seal here is comprised of an annular elastomeric member 90, surrounding a limb portion 88 and in contact with the skin thereof. Sealingly secured to the annular member 90 is an annular flange 91 extending radially outwardly therefrom. A leg portion 13a has a flange 92 at its upper end and which is held in sealing engagement with the flange 91 by a plurality of spaced bolts 95 in contact with an annular ring 96. At the upper side of the flange 91 a torso portion 11a has a flange 97 sealingly secured to the flange 91 by a plurality of spaced bolts 98 and a metal ring 101.

In FIG. 6 there is an embodiment of the invention which is particularly adaptable to increase the circulation in the limbs of a bed-rest patient. The torso portion 11b is shown to be sealingly secured to an elastomeric annular sealing member 103, formed as a right angle in cross section and having a radially extending flange 104 at the lower end. Sealingly secured to the lower side of the flange 104 is a flange 107 of an inner layer 108 snugly fitted on the leg 102. The material of the inner layer may be elastomeric so as to seal the leg and must be flexible so as to fit snugly on it. Also, sealingly secured to the lower side of the flange 104 is a flange 109 of an outer layer 112. The outer layer must be inelastic and must be adapted to hold the liquid under pressure. Between the two layers is a space 110 forming an enclosed chamber 110 about the leg. Extending through the inner layer and outer layers is a valved conduit 111. When the valve is opened pressure on the outer side of the inner layer will force air from between the skin and the inner layer to permit the inner layer to fit in direct and complete contact with the leg. The outer layer has a valved conduit 113 which is used to fill the chamber 110 with a liquid, generally water. It also may be used to empty the chamber.

In operation, a pump 65 is connected to each of the chambers 110 on the limbs and, since the layer 112 is inelastic, the pressure on all of the water therein, as well as the connections thereto, may be rapidly cycled as described in my U.S. Letters Patent No. 3,094,083, mentioned above. Such rapid cycling of pressure impulses in all of the liquid is particularly conducive to vary the pressures on the limbs through the layers 108 so as to greatly stimulate the arterial flow toward the legs when the pressure is decreased and to similarly stimulate the flow of blood toward the heart through the capillaries and veins when the pressure is increased.

In FIGS. 7 and 8, layers of generally flexible material are shown and which may be tightened on the limbs as a substitute for the relatively loose material as shown in the arm and leg portions 12 and 13 in FIG. 1. Here the material may be elastomeric and has a series of circumferentially spaced portions 114 which are adapted to be in snug fitting contact with the limb. Spaced between the portions 114 are grooves 115 formed by elongated, stiffened protrusions 116. In this structure, the grooves 115 provide passagesfor the air or gas within the limb portions of the suit and, when the pressure is increased or decreased within the limb portions, the gases will flow through the grooves so as to make the pressure changes within the limb portions effective upon the limbs to promote circulation. The material is tightened so as to be in contact with the limbs by means of the lacings 117.

In FIGS. 9 and alternate embodiments of limb portion materials are illustrated. Each of these materials are flexible and adapted to seal the limb as a part of the suit. The material shown in FIG. 9 has protrusions 118 and 119 at right angles to each other and forming grooves 120 and 121 to face the skin and provide air passages. In the same manner the material shown in FIG. 10 has protrusions 122 and crossing protrusions 123 which similarly permit the formation of grooves on the inside of the material for the air or gas passage around the limbs.

The invention and its attendant advantages will be understood from the foregoing description and it 'will be apparent that various changes may be made in the form, construction and arrangement of the parts of the invention without departing from the spirit and scope thereof or sacrificing its material advantages, the arrangement hereinbefore described being merely by way of example. I do not wish to be restricted to the specific form shown or uses mentioned except as defined in the accompanying claims, wherein various portions have been separated for clarity of reading and not for emphasis.

I claim:

1. In a pressurizable suit for enclosing a human body:

(a) a first part of a suit for sealingly enclosing the torso v and head;

(b) a second part of said suit for sealingly enclosing at least one pair of the limbs;

(c) means within said suit to seal the suit parts and the respective body parts therein from each other;

' (d) means connected to said first and second parts to supply a constant supply of life-sustaining gas to said parts at a predetermined positive life-sustaining pressure; and

(e) means connected to said second part to alternately increase and decrease pressure therein so that when the pressure is increased it is greater than the pressure in the first part and the blood flow to the heart is increased and when the pressure is decreased it is less than the pressure in the first part and the blood flow into the limbs is increased.

2. The invention according to claim 1 including:

(a) a plurality of separate valved conduits between said parts, at least one of said valves in one of said conduits being set to open at a predetermined pressure to permit said gas to flow from the first part to the second part,

(b) at least one of said valves in another of said conduits being set to open at a predetermined pressure to permit said gas to flow from the second part to the first part.

3. The invention according to claim 1 in which:

(a) said second part of said suit has substantial portions thereof in snug relationship with surfaces of said limbs,

(b) said portions being spaced by elongated passages to permit the flow of said gas along said surfaces of said limbs.

4. The invention according to claim 1 in which:

(a) said means to alternately increase and decrease the pressure in said second part includes a manually operable piston pump.

5. The invention according to claim 1 including:

(a) valve means to shut off said supply of lifesustaining gas to said second part for periods when the pressure therein is being increased and decreased.

6. The invention according to claim 5 in which:

(a) said second part is comprised of an inner and an outer layer having a sealed space therebetween adapted to be filled with water through a valved conduit,

(b) said inner layer being flexible and having a substantial part thereof being adapted to be snugly fitted on said limbs,

(c) means to vent any fluid from between said inner layer and the limbs,

(d) said means connected to said second part to alternately increase and decrease pressure therein being connected to said sealed space between said inner and outer layers so as to be adapted to vary the pressure on said limbs through said inner layer.

7. A method of promoting blood and lymph circulation in the limbs of a human being sealingly enclosed within a pressurizable suit:

(a) providing a constant supply of life-sustaining gas to the suit at a predetermined positive life-sustaining pressure;

(b) sealing the portions of the suit containing at least two of the limbs from a portion of the suit containing the head and torso so as to seal said limbs from the head and torso;

(c) alternately increasing and decreasing pressure surrounding said limbs to make it greater and less than said predetermined pressure so that the blood flow to the heart is increased when said pressure on said limbs is increased and the blood flow into said limbs is increased when said pressure on said limbs is decreased.

8. The invention according to claim 7 including the step of shutting off said constant supply of gas to said limb portions after said portions are sealed and before said pressure is increased and decreased.

9. The invention according to claim 7 including:

(a) snugly fitting said limb portions of said suit on said limbs;

(b) applying a layer of Sealing material outwardly of said suit on said limb portions to provide a sealed l chamber outwardly of said suit and said limbs; (c)filling said chamber with liquid; and (d) applying said increase and decrease of pressure to said liquid to effect said pressure changes on said limbs, said inner layer being flexible.

10. The invention according to claim 7 in which:

(a) said pressure is increased and decreased by the reciprocal pumping action of one of said limbs on a piston pump connected to said limb portion,

(b) the pressure increase occurring on movement of the piston in one direction and the decrease occurring on movement of the piston in the reciprocal direction.

References Cited UNITED STATES PATENTS 594,561 12/1897 McLean l28298 2,379,497 7/1945 Sellmeyer l281 3,094,983 6/1963 MacLeod 12840 3,158,149 11/1964 Gray 128-1 L. W. TRAPP, Primary Examiner. 

7. A MEHTOD OF PROMOTING BLOOD AND LYMPH CIRCULATION IN THE LIMBS OF A HUMAN BEING SEALINGLY ENCLOSED WITHIN A PRESSURIZABLE SUIT: (A) PROVIDING A CONSTANT SUPPLY OF LIFE-SUSTAINING GAS TO THE SUIT AT A PREDETERMINED POSITIVE LIFE-SUSTAINING PRESSURE; (B) SEALING THE PORTIONS OF THE SUIT CONTAINING AT LEAST TWO OF THE LIMBS FROM A PORTION OF THE SUIT CONTAINING THE HEAD AND TORSO SO AS TO SEAL SAID LIMBS FROM THE HEAD AND TORSO; (C) ALTERNATELY INCREASING AND DECREASING PRESSURE SURROUNDING SAID LIMBS TO MAKE IT GREATER AND LESS THAN SAID PREDETERMINED PRESSURE SO THAT THE BLOOD FLOW TO THE HEART IS INCREASED WHEN SAID PRESSURE ON SAID LIMBS IN INCREASED AND THE BLOOD FLOW INTO SAID LIMBS IS INCREASED WHEN SAID PRESSURE ON SAID LIMBS IS DECREASED. 